1. Field of the Invention
This invention relates in general to the field of data security, and more particularly to data encoding/decoding in a network.
2. Background Art
Data security is of extreme importance to all entities utilizing data processing and computing systems. As such, various data security systems are utilized to prevent unauthorized access to stored digital information. Generally, data is stored either in a central facility in a network environment, or in local computer systems' storage in a distributed environment. In either case extreme care is required to protect the data from access by intruders. Unauthorized access to the stored data can be initiated from external sources as well as internal sources without authorization to access the data, leading to copying or loss of valuable data.
With the proliferation of easily accessible networks such as the Internet, the security threat becomes much more serious to said entities as many of their computers can be accessed by outside computers through the Internet. There are sophisticated “firewall” systems that can detect any unauthorized attempt of intrusion to a particular computing system or a network of computers, and attempt to prevent unauthorized entry into the computing system. However, in many instances unauthorized intrusion into secured computing systems takes place despite the firewall systems, and valuable information lost or stolen from the computing systems.
Therefore, there have been attempts at developing systems that virtually eliminate any loss of information even in case of unauthorized intrusion into a computing system. One such system is disclosed in U.S. Pat. No. 5,136,647 issued to Stuart Harber and Wakefield Stornetta Jr. on Aug. 4, 1992, directed to a system for time-stamping a digital document. The time stamping protects the secrecy of the document text and provides a tamper proof time scale establishing an author's claim to the temporal existence of the document. The objective is to incorporate the content of the document by utilizing a one-way hash function and a time stamp into the digital data itself so that it is not possible to change any bit of the resulting time-stamp data without such a change being apparent. The author of the document does not generate the time stamping, instead the services of an independent agent are used for time stamping. A digital signature procedure is also employed by the independent agent to deter the incorporation of a false time statement. The system is primarily directed to address the need to establish the date on which a document was created and to prove that the text of a document in question is in fact is same as that of the original dated document. The system enables the detection of any alteration of the content of the digital document by examining the hash function, the time stamp and digital signature associated with the document.
Another prior art system, disclosed in U.S. Pat. No. 5,150,407 issued to Steve Chan on Sep. 22, 1992, is directed to a secured data storage device including a secured portion and a medium portion. The secured portion is a physically secured enclosure with very limited access from outside sources. The medium portion includes a conventional storage medium such as a hard disk or a floppy disk. In this system, data encoding is accomplished by utilizing an encryption algorithm and the associated key is separated into two parts, wherein the first part is stored in the secured portion of the storage device and the second part is stored in the medium portion of the storage device. This system also uses a time stamping procedure along with the encryption of the data without using an independent agent.
A further prior art system, disclosed in U.S. Pat. No. 5,289,540 issued to Richard Jones on Feb. 22, 1994, is directed to a computer file protection system. The system includes both hardware and software elements and the protection process operates by intercepting the file system data path between a central processing unit and a file storage or memory device. The system also includes a programmable auxiliary memory and auxiliary control unit.
Another prior art system, disclosed in U.S. Pat. No. 5,619,571 issued to Brent Sandstorm, et al., on Apr. 8, 1997, is directed to a system for securely storing electronic records. In this system, a data stream image identification code and time data provided by a trusted source are combined to generate a key. The image identification code and time data are stored in a public directory and a verification code is generated from the data stream. This verification code is placed in a private area that is encrypted by the key generated by the method described earlier.
Another prior art system, disclosed in U.S. Pat. No. 5,623,546 issued to Douglas Hardy, et al., on Apr. 22, 1997, is directed to an encryption method and system for portable data, wherein portable encrypted data can be accessed through multiple hosts. A split key encryption system encrypts data and stores that data on a portable device. One split of the portable key is stored in the portable device, and another split of the key is stored in the home host.
However, the above conventional systems do not address the problem of securing the stored data from intruder access, require special hardware for the secured portion of the storage device and do not support a client-server architecture.